Usually, descending equipment of large size and mass, such as manifolds, to the sea bottom in submarine oil extraction fields, especially in deep water fields, requires utilization of special vessels, provided with heavy duty cranes, vertical movement compensators (the so-called heave compensator) and/or other facilities. Such vessels, in addition of having a very high lease cost, are not always promptly available for contracting at the occasion they are needed, which may result in difficulties for the continuity of oil extracting operations.
Consequently, one of the concerns of companies engaged in oil exploration in submarine fields consists in looking for solutions, eliminating, as much as possible, the requirement for using such special vessels.